The Effects of Sound Waves on the Near Wake of a Heated Circular Cylinder

Appropriateness for the Reynolds Number Used the Fluid Kinematic Viscosity in the Film Temperature

Abstract

An experimental investigation has been carried out to study acoustic interferences in vortex-shedding from a heated circular cylinder in a crossflow subjected to the acoustical vibrations whose direction is normal to the axis of the cylinder, and in particular, to inspect the appropriateness for the Reynolds number (Re*) used the fluid kinematic viscosity in the film temperature. The results indicate that the acoustic frequencies which produce powerful effects on vortex-shedding from the heated circular cylinder correspond to the frequencies of laminar-turbulent transition wave in a separated shear layer from an isothermal circular cylinder over the Re* range. The effects of the acoustical vibrations are similar to the effects of the acoustical vibrations directed along the axis of the cylinder on the vortex-shedding, and their vibrations bring the vortex region formed in the wake close to the cylinder surface, and increase the spanwise correlation of the wake.